CD28/PD1 co-expression: dual impact on CD8+ T cells in peripheral blood and tumor tissue, and its significance in NSCLC patients' survival and ICB response.

BACKGROUND: Immune checkpoint blockade (ICB) has significantly prolonged survival of non-small cell lung cancer (NSCLC) patients, although most patients develop mechanisms of resistance. Recently single-cell RNA-sequencing (scRNA-Seq) revealed a huge T-cell phenotypic and (dys)functional state variability. Accordingly, T-cell exhaustion is recognized as a functional adaptation, with a dynamic progression from a long-lived "pre-exhausted stem-like progenitor" to a "terminally exhausted" state. In this scenario it is crucial to understand the complex interplay between co-stimulatory and inhibitory molecules in CD8+ T-cell functionality. METHODS: To gain a baseline landscape of the composition, functional states, and transcriptomic signatures predictive of prognosis, we analyzed CD8+ T-cell subsets characterized by the presence/absence of PD1 and CD28 from periphery, adjacent non-tumor tissue and tumor site of a cohort of treatment-naïve NSCLC patients, by integrated multiparametric flow cytometry, targeted multi-omic scRNA-seq analyses, and computational pipelines. RESULTS: Despite the increased PD1 levels, an improved PD1+CD28+ T-cell polyfunctionality was observed with the transition from periphery to tumor site, associated with lack of TIGIT, TIM-3 and LAG-3, but not with Ag-experienced-marker CD11a. Differently from CD28+ T cells, the increased PD1 levels in the tumor were associated with reduced functionality in PD1+CD28- T cells. CD11ahigh, although expressed only in a small fraction of this subset, still sustained its functionality. Absence of TIGIT, TIM-3 and CTLA-4, alone or combined, was beneficial to CD28- T cells. Notably, we observed distinct TRM phenotypes in the different districts, with CD28+ T cells more capable of producing TGFß in the periphery, potentially contributing to elevated CD103 levels. In contrast CD28- TRM mainly produced CXCL13 within the tumor. ScRNA-seq revealed 5 different clusters for each of the two subsets, with distinctive transcriptional profiles in the three districts. By interrogating the TCGA dataset of patients with lung adenocarcinoma (LUAD) and metastatic NSCLC treated with atezolizumab, we found signatures of heterogeneous TRM and "pre-exhausted" long-lived effector memory CD8+ T cells associated with improved response to ICB only in the presence of CD28. CONCLUSIONS: Our findings identify signatures able to stratify survival of LUAD patients and predict ICB response in advanced NSCLC. CD28 is advocated as a key determinant in the signatures identified, in both periphery and tumor site, thus likely providing feasible biomarkers of ICB response.

CD27 agonism coordinates with CD28 and 4-1BB signal to augment the efficacy of CAR-T cells in colorectal tumor.

Chimeric antigen receptor T cell (CAR-T) is regarded as a promising therapy for malignancies. In our previous clinical trial targeted colorectal tumors, we found that CAR-T cells experienced poor proliferation and persistence in tumor sites. To improve the efficacy of CAR-T cells, we introduced CD27 co-stimulation signal into the established system and found that the CEA28BB27Z CAR-T cells exhibited enhanced proliferation and anti-tumor activity. Next, we demonstrated that the CEA28BB27Z CAR-T cells expressed less immune checkpoint receptors and generated more CD4+ and CD8+ memory stem T (TSCM) cells compared with other CARs during constant antigen stimulation. Furthermore, our data revealed that the different combination of co-stimulation signal affected the mitochondrial dynamics of CAR-T cells, and CEA28BB27Z CAR-T cells maintained more fused mitochondrial network compared with others. Finally, we validated the superior antitumor capacity of the CEA28BB27Z CAR-T cells in xenograft models. Our findings suggest that CD27 co-stimulation signals play a key role in improving the anti-tumor efficacy of CAR-T cells.

Systemic Administration of Acazicolcept, a Dual CD28 and Inducible T cell Costimulator Inhibitor, Ameliorates Experimental Autoimmune Uveitis.

Purpose: Combined inhibition of CD28 and inducible T cell costimulator (ICOS) pathways with acazicolcept (ALPN-101) represents a potential new treatment for uveitis. Here, we evaluate preclinical efficacy using experimental autoimmune uveitis (EAU) in Lewis rats. Methods: Efficacy was tested in 57 Lewis rats treated with either systemic (subcutaneous) or local (intravitreal) administration of acazicolcept and compared to treatment with a matched Fc-only control or corticosteroid. Impact of treatment on uveitis was assessed using clinical scoring, optical coherence tomography (OCT), and histology. Ocular effector T cell populations were determined using flow cytometry, and multiplex ELISA used to measure aqueous cytokine concentrations. Results: When compared to Fc control treatment, systemic acazicolcept led to statistically significant decreases in clinical score (P < 0.01), histologic score (P < 0.05), and number of ocular CD45+ cells (P < 0.01). Number of ocular CD4+ and CD8+ T cells expressing IL-17A+ and IFNγ+ were also decreased with statistical significance (P < 0.01). Similar results were achieved with corticosteroids. Intravitreal acazicolcept decreased inflammation scores when compared to untreated fellow eyes and to Fc control treated eyes, although not statistically significant. Systemic toxicity, measured by weight loss, occurred in the corticosteroid-treated, but not in the acazicolcept-treated animals. Conclusions: Systemic treatment with acazicolcept statistically significantly suppressed EAU. Acazicolcept was well-tolerated without the weight loss associated with corticosteroids. Acazicolcept may be an effective alternative to corticosteroids for use in treating autoimmune uveitis. Additional studies are needed to clarify the optimal dose and route for use in humans. Translational Relevance: We show that T cell costimulatory blockade could be an effective mechanism for treating uveitis.

Oral administration of Helianthus annuus leaf extract ameliorates atopic dermatitis by modulation of T cell activity in vivo.

BACKGROUND: Atopic dermatitis (AD) is multifactorial disease that is highly involved in the activity of T cells from the skin lesion. Seeds of Helianthus annuus extract have been traditionally used as anti-inflammatory reagent but few studies have been reported on leaf of H. annuus that are discarded uselessly as an immunomodulator. PURPOSE: Therefore, here, the regulatory effect of Helianthus annuus extract (HAE) on AD via suppression of T cell activity was investigated. METHODS: The efficacy of HAE was evaluated in T cells stimulated with CD3/CD28 antibody and PMA/A23187. And demonstration of the alleviating effect of HAE on AD in the ears of Balb/c female mice stimulated with mite extract and DNCB. RESULTS: Pre-treatment with HAE abrogates IL-2 production from activated T cells. It was also found that HAE suppresses the expression of surface molecules in activated T cells. Cell viability results demonstrated that HAE is not associated with cytotoxicity in resting and activated T cells. Besides, we exhibited that regulated phosphorylation of MAPK through TAK1-IKKα-NFκB by pre-treatment with HAE leads to the suppressive effect of HAE on T cell activation. Oral administration of HAE attenuates manifestations of AD including reduced thickness of dermis and epidermis, decreased IgE level in serum, and declined mRNA levels of atopic cytokines on ear tissues. The ameliorative effect of HAE on AD was found to be associated with suppressed activity of T cells from draining lymph nodes. CONCLUSION: Therefore, our results provide that HAE alleviates AD symptoms via modulation of T cell activity. In addition, these results suggest the immunomodulatory effect of HAE on T-cell mediated diseases.

Two cases of ulcerative colitis that developed while using abatacept.

Abatacept (ABT) is a recombinant fusion protein consisting of the Fc domain fragment of human IgG1 and the extracellular domain of human cytotoxic T lymphocyte antigen-4 (CTLA-4). The function of ABT is similar to that of CTLA-4, which selectively regulates T-cell activation by inhibiting the co-stimulation of CD80/CD86 on antigen-presenting cells and CD28 on T lymphocytes. ABT is used for the treatment of rheumatoid arthritis (RA) and juvenile idiopathic arthritis. We report two cases of ulcerative colitis (UC) that developed while using ABT. Case 1 is of a 58-year-old man who developed diarrhea and hematochezia 2 months after starting ABT therapy for RA. Case 2 is of a 66-year-old man who experienced hematochezia 15 months after starting ABT therapy for RA. In both cases, no obvious gastrointestinal symptoms were observed before ABT therapy was initiated. Colonoscopy after disease onset showed UC findings in both cases. The patients' condition improved following ABT withdrawal and treatment for UC. Several cases of UC development during ABT therapy have been reported. The complication of UC should be considered when diarrhea and hematochezia are observed in patients with RA being treated with CTLA-4Ig agents.

New insights into checkpoint inhibitor immunotherapy and its combined therapies in hepatocellular carcinoma: from mechanisms to clinical trials.

Hepatocellular carcinoma (HCC) is one of the most lethal tumors in China and worldwide, although first-line therapies for HCC, such as atezolizumab and bevacizumab, have been effective with good results, the researches on new therapies have attracted much attention. With the deepening research on tumor immunology, the role and operation mechanism of immune cells in the tumor microenvironment (TME) of HCC have been explained, such as programmed cell death protein 1 (PD-1) binding to ligand could cause T cell exhaustion and reduce IFN-γ T cell secretion, cytotoxic T lymphocyte 4 (CTLA-4) and CD28 mediate immunosuppression by competing for B7 protein and disrupting CD28 signal transduction pathway, which also lays the foundation for the development and application of more new immune checkpoint inhibitors (ICIs). The biological behavior of various immune checkpoints has been proved in HCC, such as PD-1, programmed cell death ligand 1 (PD-L1), CTLA-4 and so on, leading to a series of clinical trials. Currently, FDA approved nivolumab, pembrolizumab and nivolumab plus ipilimumab for the treatment of HCC. However, the treatment of ICI has the disadvantages of low response rate and many side effects, so the combination of ICIs and various other therapies (such as VEGF or VEGFR inhibition, neoadjuvant and adjuvant therapy, locoregional therapies) has been derived. Further studies on immune checkpoint mechanisms may reveal new therapeutic targets and new combination therapies in the future.

Treatment of patients with relapsed or refractory CD19+ lymphoid disease with T lymphocytes transduced by RV-SFG.CD19.CD28.4-1BBzeta retroviral vector: a unicentre phase I/II clinical trial protocol.

INTRODUCTION: Chimeric antigen receptor (CAR) T cells spark hope for patients with CD19+ B cell neoplasia, including relapsed or refractory (r/r) acute lymphoblastic leukaemia (ALL) or r/r non-Hodgkin's lymphoma (NHL). Published studies have mostly used second-generation CARs with 4-1BB or CD28 as costimulatory domains. Preclinical results of third-generation CARs incorporating both elements have shown superiority concerning longevity and proliferation. The University Hospital of Heidelberg is the first institution to run an investigator-initiated trial (IIT) CAR T cell trial (Heidelberg Chimeric Antigen Receptor T cell Trial number 1 [HD-CAR-1]) in Germany with third-generation CD19-directed CAR T cells. METHODS AND ANALYSIS: Adult patients with r/r ALL (stratum I), r/r NHL including chronic lymphocytic leukaemia, diffuse large B-cell lymphoma, follicular lymphoma or mantle cell lymphoma (stratum II) as well as paediatric patients with r/r ALL (stratum III) will be treated with autologous T-lymphocytes transduced by third-generation RV-SFG.CD19.CD28.4-1BB zeta retroviral vector (CD19.CAR T cells). The main purpose of this study is to evaluate safety and feasibility of escalating CD19.CAR T cell doses (1-20×106 transduced cells/m2) after lymphodepletion with fludarabine (flu) and cyclophosphamide (cyc). Patients will be monitored for cytokine release syndrome (CRS), neurotoxicity, i.e. CAR-T-cell-related encephalopathy syndrome (CRES) and/or other toxicities (primary objectives). Secondary objectives include evaluation of in vivo function and survival of CD19.CAR T cells and assessment of CD19.CAR T cell antitumour efficacy.HD-CAR-1 as a prospective, monocentric trial aims to make CAR T cell therapy accessible to patients in Europe. Currently, HD-CAR-1 is the first and only CAR T cell IIT in Germany. A third-generation Good Manufacturing Practice (GMP) grade retroviral vector, a broad spectrum of NHL, treatment of paediatric and adult ALL patients and inclusion of patients even after allogeneic stem cell transplantation (alloSCT) make this trial unique. ETHICS AND DISSEMINATION: Ethical approval and approvals from the local and federal competent authorities were granted. Trial results will be reported via peer-reviewed journals and presented at conferences and scientific meetings. TRIAL REGISTRATION NUMBER: Eudra CT 2016-004808-60; NCT03676504; Pre-results.

Interventions for necrotizing soft tissue infections in adults.

BACKGROUND: Necrotizing soft tissue infections (NSTIs) are severe and rapidly spreading soft tissue infections of the subcutaneous tissue, fascia, or muscle, which are mostly caused by bacteria. Associated rates of mortality and morbidity are high, with the former estimated at around 23%, and disability, sequelae, and limb loss occurring in 15% of patients. Standard management includes intravenous empiric antimicrobial therapy, early surgical debridement of necrotic tissues, intensive care support, and adjuvant therapies such as intravenous immunoglobulin (IVIG). OBJECTIVES: To assess the effects of medical and surgical treatments for necrotizing soft tissue infections (NSTIs) in adults in hospital settings. SEARCH METHODS: We searched the following databases up to April 2018: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trials registers, pharmaceutical company trial results databases, and the US Food and Drug Administration and the European Medicines Agency websites. We checked the reference lists of included studies and reviews for further references to relevant randomised controlled trials (RCTs). SELECTION CRITERIA: RCTs conducted in hospital settings, that evaluated any medical or surgical treatment for adults with NSTI were eligible for inclusion. Eligible medical treatments included 1) comparisons between different antimicrobials or with placebo; 2) adjuvant therapies such as intravenous immunoglobulin (IGIV) therapy compared with placebo; no treatment; or other adjuvant therapies. Eligible surgical treatments included surgical debridement compared with amputation, immediate versus delayed intervention, or comparisons of number of interventions.RCTs of hyperbaric oxygen (HBO) therapy for NSTI were ineligible because HBO is the focus of another Cochrane Review. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. The primary outcome measures were 1) mortality within 30 days, and 2) proportion of participants who experience a serious adverse event. Secondary outcomes were 1) survival time, and 2) assessment of long-term morbidity. We used GRADE to assess the quality of the evidence for each outcome. MAIN RESULTS: We included three trials randomising 197 participants (62% men) who had a mean age of 55 years. One trial compared two antibiotic treatments, and two trials compared adjuvant therapies with placebo. In all trials, participants concomitantly received standard interventions, such as intravenous empiric antimicrobial therapy, surgical debridement of necrotic tissues, intensive care support, and adjuvant therapies. All trials were at risk of attrition bias and one trial was not blinded.Moxifloxacin versus amoxicillin-clavulanate One trial included 54 participants who had a NSTI; it compared a third-generation quinolone, moxifloxacin, at a dose of 400 mg given once daily, against a penicillin, amoxicillin-clavulanate, at a dose of 3 g given three times daily for at least three days, followed by 1.5 g three times daily. Duration of treatment varied from 7 to 21 days. We are uncertain of the effects of these treatments on mortality within 30 days (risk ratio (RR) 3.00, 95% confidence interval (CI) 0.39 to 23.07) and serious adverse events at 28 days (RR 0.63, 95% CI 0.30 to 1.31) because the quality of the evidence is very low.AB103 versus placebo One trial of 43 randomised participants compared two doses, 0.5 mg/kg and 0.25 mg/kg, of an adjuvant drug, a CD28 antagonist receptor (AB103), with placebo. Treatment was given via infusion pump for 10 minutes before, after, or during surgery within six hours after the diagnosis of NSTI. We are uncertain of the effects of AB103 on mortality rate within 30 days (RR of 0.34, 95% CI 0.05 to 2.16) and serious adverse events measured at 28 days (RR 1.49, 95% CI 0.52 to 4.27) because the quality of the evidence is very low.Intravenous immunoglobulin (IVIG) versus placebo One trial of 100 randomised participants assessed IVIG as an adjuvant drug, given at a dose of 25 g/day, compared with placebo, given for three consecutive days. There may be no clear difference between IVIG and placebo in terms of mortality within 30 days (RR 1.17, 95% CI 0.42 to 3.23) (low-certainty evidence), nor serious adverse events experienced in the intensive care unit (ICU) (RR 0.73 CI 95% 0.32 to 1.65) (low-certainty evidence).Serious adverse events were only described in one RCT (the IVIG versus placebo trial) and included acute kidney injury, allergic reactions, aseptic meningitis syndrome, haemolytic anaemia, thrombi, and transmissible agents.Only one trial reported assessment of long-term morbidity, but the outcome was not defined in the way we prespecified in our protocol. The trial used the Short Form Health Survey (SF36). Data on survival time were provided upon request for the trials comparing amoxicillin-clavulanate versus moxifloxacin and IVIG versus placebo. However, even with data provided, it was not possible to perform survival analysis. AUTHORS' CONCLUSIONS: We found very little evidence on the effects of medical and surgical treatments for NSTI. We cannot draw conclusions regarding the relative effects of any of the interventions on 30-day mortality or serious adverse events due to the very low quality of the evidence.The quality of the evidence is limited by the very small number of trials, the small sample sizes, and the risks of bias in the included trials. It is important for future trials to clearly define their inclusion criteria, which will help with the applicability of future trial results to a real-life population.Management of NSTI participants (critically-ill participants) is complex, involving multiple interventions; thus, observational studies and prospective registries might be a better foundation for future research, which should assess empiric antimicrobial therapy, as well as surgical debridement, along with the placebo-controlled comparison of adjuvant therapy. Key outcomes to assess include mortality (in the acute phase of the condition) and long-term functional outcomes, e.g. quality of life (in the chronic phase).

Aberrant Lck Signal via CD28 Costimulation Augments Antigen-Specific Functionality and Tumor Control by Redirected T Cells with PD-1 Blockade in Humanized Mice.

Purpose: Combination therapy of adoptively transferred redirected T cells and checkpoint inhibitors aims for higher response rates in tumors poorly responsive to immunotherapy like malignant pleural mesothelioma (MPM). Only most recently the issue of an optimally active chimeric antigen receptor (CAR) and the combination with checkpoint inhibitors is starting to be addressed.Experimental Design: Fibroblast activation protein (FAP)-specific CARs with different costimulatory domains, including CD28, Δ-CD28 (lacking lck binding moiety), or 4-1BB were established. CAR-T cells were characterized in vitro and antitumor efficacy was tested in vivo in a humanized mouse model in combination with PD-1 blockade. Finally, the Δ-CD28 CAR was tested clinically in a patient with MPM.Results: All the three CARs demonstrated FAP-specific functionality in vitro Gene expression data indicated a distinct activity profile for the Δ-CD28 CAR, including higher expression of genes involved in cell division, glycolysis, fatty acid oxidation, and oxidative phosphorylation. In vivo, only T cells expressing the Δ-CD28 CAR in combination with PD-1 blockade controlled tumor growth. When injected into the pleural effusion of a patient with MPM, the Δ-CD28 CAR could be detected for up to 21 days and showed functionality.Conclusions: Overall, anti-FAP-Δ-CD28/CD3ζ CAR T cells revealed superior in vitro functionality, better tumor control in combination with PD-1 blockade in humanized mice, and persistence up to 21 days in a patient with MPM. Therefore, further clinical investigation of this optimized CAR is warranted. Clin Cancer Res; 24(16); 3981-93. ©2018 AACR.

Efficient Non-Viral T-Cell Engineering by Sleeping Beauty Minicircles Diminishing DNA Toxicity and miRNAs Silencing the Endogenous T-Cell Receptors.

Transposon-based vectors have entered clinical trials as an alternative to viral vectors for genetic engineering of T cells. However, transposon vectors require DNA transfection into T cells, which were found to cause adverse effects. T-cell viability was decreased in a dose-dependent manner, and DNA-transfected T cells showed a delayed response upon T-cell receptor (TCR) stimulation with regard to blast formation, proliferation, and surface expression of CD25 and CD28. Gene expression analysis demonstrated a DNA-dependent induction of a type I interferon response and interferon-ß upregulation. By combining Sleeping Beauty transposon minicircle vectors with SB100X transposase-encoding RNA, it was possible to reduce the amount of total DNA required, and stable expression of therapeutic TCRs was achieved in >50% of human T cells without enrichment. The TCR-engineered T cells mediated effective tumor cell killing and cytokine secretion upon antigen-specific stimulation. Additionally, the Sleeping Beauty transposon system was further improved by miRNAs silencing the endogenous TCR chains. These miRNAs increased the surface expression of the transgenic TCR, diminished mispairing with endogenous TCR chains, and enhanced antigen-specific T-cell functionality. This approach facilitates the rapid non-viral generation of highly functional, engineered T cells for immunotherapy.

A novel chimeric antigen receptor containing a JAK-STAT signaling domain mediates superior antitumor effects.

The adoptive transfer of T cells engineered with a chimeric antigen receptor (CAR) (hereafter referred to as CAR-T cells) specific for the B lymphocyte antigen CD19 has shown impressive clinical responses in patients with refractory B cell malignancies. However, the therapeutic effects of CAR-T cells that target other malignancies have not yet resulted in significant clinical benefit. Although inefficient tumor trafficking and various immunosuppressive mechanisms can impede CAR-T cell effector responses, the signals delivered by the current CAR constructs may still be insufficient to fully activate antitumor T cell functions. Optimal T cell activation and proliferation requires multiple signals, including T cell receptor (TCR) engagement (signal 1), co-stimulation (signal 2) and cytokine engagement (signal 3). However, CAR constructs currently being tested in the clinic contain a CD3z (TCR signaling) domain and co-stimulatory domain(s) but not a domain that transmits signal 3 (refs. 13, 14, 15, 16, 17, 18). Here we have developed a novel CAR construct capable of inducing cytokine signaling after antigen stimulation. This new-generation CD19 CAR encodes a truncated cytoplasmic domain from the interleukin (IL)-2 receptor ß-chain (IL-2Rß) and a STAT3-binding tyrosine-X-X-glutamine (YXXQ) motif, together with the TCR signaling (CD3z) and co-stimulatory (CD28) domains (hereafter referred to as 28-ΔIL2RB-z(YXXQ)). The 28-ΔIL2RB-z(YXXQ) CAR-T cells showed antigen-dependent activation of the JAK kinase and of the STAT3 and STAT5 transcription factors signaling pathways, which promoted their proliferation and prevented terminal differentiation in vitro. The 28-ΔIL2RB-z(YXXQ) CAR-T cells demonstrated superior in vivo persistence and antitumor effects in models of liquid and solid tumors as compared with CAR-T cells expressing a CD28 or 4-1BB co-stimulatory domain alone. Taken together, these results suggest that our new-generation CAR has the potential to demonstrate superior antitumor effects with minimal toxicity in the clinic and that clinical translation of this novel CAR is warranted.

Redirecting T Cells to Glypican-3 with 4-1BB Zeta Chimeric Antigen Receptors Results in Th1 Polarization and Potent Antitumor Activity.

T cells engineered to express CD19-specific chimeric antigen receptors (CARs) have shown breakthrough clinical successes in patients with B-cell lymphoid malignancies. However, similar therapeutic efficacy of CAR T cells in solid tumors is yet to be achieved. In this study we systematically evaluated a series of CAR constructs targeting glypican-3 (GPC3), which is selectively expressed on several solid tumors. We compared GPC3-specific CARs that encoded CD3ζ (Gz) alone or with costimulatory domains derived from CD28 (G28z), 4-1BB (GBBz), or CD28 and 4-1BB (G28BBz). All GPC3-CARs rendered T cells highly cytotoxic to GPC3-positive hepatocellular carcinoma, hepatoblastoma, and malignant rhabdoid tumor cell lines in vitro. GBBz induced the preferential production of Th1 cytokines (interferon γ/granulocyte macrophage colony-stimulating factor) while G28z preferentially induced Th2 cytokines (interleukin-4/interleukin-10). Inclusion of 4-1BB in G28BBz could only partially ameliorate the Th2-polarizing effect of CD28. 4-1BB induced superior expansion of CAR T cells in vitro and in vivo. T cells expressing GPC3-CARs incorporating CD28, 4-1BB, or both induced sustained tumor regressions in two xenogeneic tumor models. Thus, GBBz CAR endows T cells with superior proliferative potential, potent antitumor activity, and a Th1-biased cytokine profile, justifying further clinical development of GBBz CAR for immunotherapy of GPC3-positive solid tumors.

Update on the Protective Role of Regulatory T Cells in Myocardial Infarction: A Promising Therapy to Repair the Heart.

Myocardial infarction (MI) remains one of the leading causes of heart failure development and death worldwide. To date, interventional and pharmacological therapies are effective in reducing the onset of heart failure and promoting survival. However, progressive maladaptive remodeling post-MI persists in a large fraction of patients resulting in poor prognosis. Immune cell responses and an inflammatory environment largely contribute to adverse cardiac remodeling post-MI. CD4FOXP3 regulatory T cells (Tregs) are known for their immunosuppressive capacity and have been successfully implemented in multiple preclinical studies of permanent and ischemia-reperfusion MI. In this review, we highlight the important cardioprotective role of Tregs at the cardiac tissue, cellular, and molecular level, as well as the most prominent pharmacological venues that could be used to exploit Tregs as a novel therapeutic intervention to lessen myocardial injury post-MI.

The pharmacology of second-generation chimeric antigen receptors.

Second-generation chimeric antigen receptors (CARs) retarget and reprogramme T cells to augment their antitumour efficacy. The combined activating and co-stimulatory domains incorporated in these CARs critically determine the function, differentiation, metabolism and persistence of engineered T cells. CD19-targeted CARs that incorporate CD28 or 4-1BB signalling domains are the best known to date. Both have shown remarkable complete remission rates in patients with refractory B cell malignancies. Recent data indicate that CD28-based CARs direct a brisk proliferative response and boost effector functions, whereas 4-1BB-based CARs induce a more progressive T cell accumulation that may compensate for less immediate potency. These distinct kinetic features can be exploited to further develop CAR-based T cell therapies for a variety of cancers. A new field of immunopharmacology is emerging.

CD28 homodimer interface mimetic peptide acts as a preventive and therapeutic agent in models of severe bacterial sepsis and gram-negative bacterial peritonitis.

BACKGROUND: Severe gram-negative bacterial infections and sepsis are major causes of morbidity and mortality. Dysregulated, excessive proinflammatory cytokine expression contributes to the pathogenesis of sepsis. A CD28 mimetic peptide (AB103; previously known as p2TA) that attenuates CD28 signaling and T-helper type 1 cytokine responses was tested for its ability to increase survival in models of polymicrobial infection and gram-negative sepsis. METHODS: Mice received AB103, followed by an injection of Escherichia coli 0111:B4 lipopolysaccharide (LPS); underwent induction E. coli 018:K1 peritonitis induction, followed by treatment with AB103; or underwent cecal ligation and puncture (CLP), followed by treatment with AB103. The effects of AB103 on factors associated with and the lethality of challenge infections were analyzed. RESULTS: AB103 strongly attenuated induction of tumor necrosis factor α and interleukin 6 (IL-6) by LPS in human peripheral blood mononuclear cells. Receipt of AB103 following intraperitoneal injection of LPS resulted in survival among 73% of CD1 mice (11 of 15), compared with 20% of controls (3 of 15). Suboptimal doses of antibiotic alone protected 20% of mice (1 of 5) from E. coli peritonitis, whereas 100% (15 of 15) survived when AB103 was added 4 hours following infection. Survival among mice treated with AB103 12 hours after CLP was 100% (8 of 8), compared with 17% among untreated mice (1 of 6). In addition, receipt of AB103 12 hours after CLP attenuated inflammatory cytokine responses and neutrophil influx into tissues and promoted bacterial clearance. Receipt of AB103 24 hours after CLP still protected 63% of mice (5 of 8). CONCLUSIONS: Single-dose AB103 reduces mortality in experimental models of polymicrobial and gram-negative bacterial infection and sepsis, warranting further studies of this agent in clinical trials.

A Novel Drug for Treatment of Necrotizing Soft-Tissue Infections: A Randomized Clinical Trial.

IMPORTANCE: Necrotizing soft-tissue infections (NSTI) have high morbidity and mortality rates despite aggressive surgical debridement and antibiotic therapy. AB103 is a peptide mimetic of the T-lymphocyte receptor, CD28. We hypothesized that AB103 will limit inflammatory responses to bacterial toxins and decrease the incidence of organ failure. OBJECTIVES: To establish the safety of AB103 in patients with NSTI and evaluate the potential effects on clinically meaningful parameters related to the disease. DESIGN, SETTING, AND PARTICIPANTS: A prospective, randomized, placebo-controlled, double-blinded study was performed in 6 academic medical centers in the United States. Participants included adults with NSTI. Of 345 patients screened, 43 were enrolled for the intent-to-treat analysis, and 40 met criteria for the modified intent-to-treat analysis; 15 patients each were included in the high-dose and low-dose treatment arms, and 10 in the placebo arm. INTERVENTION: Single intravenous dose of AB103 (0.5 or 0.25 mg/kg) within 6 hours after diagnosis of NSTI. MAIN OUTCOMES AND MEASURES: Change in the Sequential Organ Failure Assessment score within 28 days, intensive care unit-free and ventilator-free days, number and timing of debridements, plasma and tissue cytokine levels at 0 to 72 hours, and adverse events. RESULTS: Baseline characteristics were comparable in the treatment groups. The Sequential Organ Failure Assessment score improved from baseline in both treatment groups compared with the placebo group at 14 days (change from baseline score, -2.8 in the high-dose, -2 in the low-dose, and +1.3 in the placebo groups; P = .04). AB103-treated patients had a similar number of debridements (mean [SD], 2.2 [1.1] for the high-dose, 2.3 [1.2] for the low-dose, and 2.8 [2.1] for the placebo groups; P = .56). There were no statistically significant differences in intensive care unit-free and ventilator-free days or in plasma and tissue cytokine levels. No drug-related adverse events were detected. CONCLUSIONS AND RELEVANCE: AB103 is a safe, promising new agent for modulation of inflammation after NSTI. Further study is warranted to establish efficacy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01417780.

CD28z CARs and armored CARs.

CD19-targeted chimeric antigen receptor (CAR) T cells are currently being tested in the clinic with very promising outcomes. However, limitations to CAR T cell therapy exist. These include lack of efficacy against some tumors, specific targeting of tumor cells without affecting normal tissue and retaining activity within the suppressive tumor microenvironment. Whereas promising clinical trials are in progress, preclinical development is focused on optimizing CAR design, to generate "armored CAR T cells," which are protected from the inhibitory tumor microenvironment. Studies investigating the expression of cytokine transgenes, combination therapy with small molecule inhibitors, or monoclonal antibodies, are aimed at improving the antitumor efficacy of CAR T cell therapy. Other strategies aimed at improving CAR T cell therapy include using dual CARs and chemokine receptors to more specifically target tumor cells. This review will describe the current clinical data and some novel armored CAR T cell approaches for improving antitumor efficacy therapy.